Elderly patients with persistent unexplained fever require a diagnostic evaluation that focuses on specific infections (eg, occult abdominal abscess, bacterial endocarditis, miliary tuberculosis), rheumatic disorders (eg, temporal arteritis, polyarteritis nodosa), and neoplasms (eg, lymphoma, nephroma). Assessment is directed by the subtle dues elicited from meticulous, repeated history taking and physical examination. Therapeutic trials or exploratory laparotomy may be appropriate but should not be attempted out of a sense of frustration.